Cabot’s After-School Math Puzzle Club

Will Brockman is a software engineer at Google Cambridge, a math Ph.D., and a parent of two boys at Cabot Elementary School in Newtonville. With three other parents, he leads an after-school “math puzzle club” for 4th and 5th graders, where kids do math contest puzzles for practice and in contest settings. This year, the kids have taken the 5 Elementary Math Olympiad contests and the Math League contest.  Here’s how it works…

The parents, seeing how excited their children were by competitions, approached Cabot principal Jim Swaim with the idea of doing math contests as an after-school math enrichment activity. As Will explains, “We didn’t want to compete with the school’s math teachers; they’re great. It’s risky to move kids ahead in the curriculum, because you don’t want them to get bored in school. In our club, we’re not teaching, but rather encouraging kids to experience through puzzles the math they know. This shows kids what they can do with what they have learned in school.”

Here are some questions the kids tackled in a recent Olympiad:

  • How many digits are in the product 2 x 3 x 5 x 2 x 3 x 5 x 2 x 3 x 5?
  • How many 3-digit numbers have exactly 2 digits the same?

Each Wednesday afternoon, the kids spend about 45 minutes practicing with math puzzles, in self-selected groups, at their own pace. “We didn’t have to teach about working together, since the kids already learned that in school,” Will said. Despite the fact that the kids work on math contests alone, the adults focus on the team results, emphasizing the positive contributions of each team member.

All are very pleased with how this is working. In its first year, the Cabot team scored in the top 25% of 3,057 teams taking the contest. The kids are enthusiastic and committed, with 20 kids attending practices regularly, 15 taking the contests, and all showing substantial progress in the course of the year. One went from being too nervous to take the contest in January to getting 4 out of 5 questions right in March.

The group uses Math Olympiads as its main source of math contest problems and supporting materials, using the shorter Math League problems as warm-ups. Out-of-pocket costs (about $35 for a book of problem sets, plus $150 to enter two contests) were paid by the PTO.

This requires considerable commitment by the parents, however. They have committed to having 3 of the 4 attending every session, so it takes a significant amount of their time. But the payoff makes it worthwhile! Anyone interested in learning more may email Will Brockman at